I will explain you first the difference of organic and paid search;
1- Organic Search
Organic search is said to the resulted links appeared before a user on search engine result pages or aka SREPs when he hit on search button.
2- Paid Search
Paid search is the advertisement links that will be appeared either before organic search or on right or sometime on the left side of organic search of a SREP.
To attain a rank for the organic search for your website or blog you have to do a little on page optimization techniques if you already know that just give a look to your site or blog that whether you forget any important part of on page optimization so that you can not attain your desired traffic or other wise if you do not know then just put this phrase "on page optimization" in search bar of any search engine you like and read about that and then apply it to your blog or website, anyway but I will tell a little more about "on page optimization".
To attain on page optimization you will have to notice following important tips.
1- Put at least one time your keyword or niche in title of your blog or website.
2- Repeat at least one time more the keyword in the description of your site.
3- Use your keyword or niche in the content of page at least one and not more than 3 or time.
4- You may also use your keyword at the bottom of the page but remember it will be in a manner that create a sense of understanding other wise search engine will through your site out of its directory.
I have a power full tool that I have been using since 6 months and it helps me a lot to attain a sustainable position at organic search at all leading search engines on internet hope you will find it help full too.
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SEO Power Team